Several of the hundred-foot-long girders were already in place by Saturday, July 12, 2014. The girders will support the weight of the Park Over the Highway connecting the Old Courthouse to the arch grounds.

Once completed, the Park Over the Highway will connect the Old Courthouse with the arch grounds.

Camille Phillips/St. Louis Public Radio

A major step in the Gateway Arch grounds renovation is taking place this weekend, causing road closures and detours in downtown St. Louis.

Working around the clock from Friday night until Monday morning, Missouri Department of Transportation crews are placing 40 large girders over the depressed lanes of I-44. It’s the first step in building the land bridge that will connect downtown St. Louis with the Arch grounds.

Once the land bridge is complete, visitors will be able to walk or bike from the Old Courthouse to the Arch without having to stop for traffic. Currently pedestrians have to cross two intersections to reach the Arch grounds.

“For the first time in the arch’s history, we’ll be able to connect the Arch grounds to St. Louis, so it’s really, really important work, and it’s going to allow the public to really get the first view at this structure and where it’s going to be,” said Ryan McClure of the CityArchRiver 2015 Foundation.

Construction of the land bridge is slated for completion by the end of the year. Once all the metal and concrete is in place, dirt and plants will be brought in to create an inviting, park-like atmosphere.

According to McClure, MoDot deserves a lot of credit for working with CityArchRiver project designers MVVA to create a design that accommodates such extensive landscaping.

“They worked with MVVA to find ways to actually plant trees on this structure. The design and the engineering is unique and very creative,” said McClure.

According to MoDot Area Engineer Deanna Venker, MoDot took MVVA’s conceptual idea and figured out how to engineer it.

“Their concepts and their designs were utilized in the engineering drawings that were used to come up with the design for the entirety of how we anchor the trees to the deck, to the retaining walls located on the sides of the bridge structure, to the railings, to the light post, to everything that’s associated with the bridge itself,” she said.

By Saturday, girder placement was well underway, letting Arch-goers visualize the shape of the future bridge.

As a history teacher, Derrick McIntosh wanted to take six-year-old Regina McIntosh on a quick trip from Memphis to see the Arch. They didn’t know about the construction before they arrived, but they weren’t too fazed by it.

Once the Park Over the Highway concept was described to him, Derrick McIntosh thought it was a neat idea.

“That’s actually probably better because it can be like an outside venue, you can have outside festivals and events,” he said. “That’s pretty cool.”